TRANSDUCER OF AN ELECTRICAL INPUT SIGNAL INTO PNEUMATIC OUTPUT SIGNALS

Abstract

In a transducer of at least one electrical input signal into two separate magnetic output signals for a pneumatic actuator, a pressure input is connected to a source of pressure and a setting unit sets the pneumatic output signals by use of the electrical input signal. The setting unit provides the two pneumatic output signals separately and reciprocal to each other as a function of the input signal. At least one of the two output signals is connected to a pneumatic amplifier.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block circuit diagram of a pneumatic actuator system with an I/P transducer in accordance with the preferred embodiment, two pneumatic amplifiers and a pneumatic actuator;

FIG. 2 a is a block circuit diagram of the transducer in accordance with the preferred embodiment as shown in FIG. 1;

FIG. 2 b is a graph showing the characteristic curves of the pneumatic output signals of the transducer in accordance with the preferred embodiment as shown in FIG. 2a;

FIG. 3 a is a block circuit diagram of an alternative aspect of an I/P transducer in accordance with the preferred embodiment; and

FIG. 3 b is a graph showing the characteristic curves of the pneumatic output signals of the I/P transducer in accordance with the preferred embodiment as shown in FIG. 3a.

Claims

1. A transducer of at least one electrical input signal into two separate magnetic output signals for a pneumatic actuator, comprising: a pressure input connected to a source of pressure and a setting unit setting the pneumatic output signals by use of the electrical input signal;the setting unit providing the two pneumatic output signals separately and reciprocal to each other as a function of the input signal; andat least one of the two output signals being connected to a pneumatic amplifier.

2. A transducer of claim 1 wherein the setting unit has connected to the pressure source two separate pneumatic conduits connected to each output and two control elements setting a pneumatic pressure at an output of each pneumatic conduit, the two control elements having a reciprocal response.

3. A transducer of claim 1 wherein at least one control element is provided controlled by the electrical input signal.

4. A transducer of claim 1 wherein the setting unit comprises a nozzle-flapper assembly with two nozzles connected to the pressure input, pressure being variable at the nozzles by use of respective control elements.

5. A transducer of claim 4 wherein each nozzle has a variable restrictor before an input thereof.

6. A transducer of claim 4 wherein a flapper comprising first and second rocker arms of the nozzle-flapper assembly is rocker mounted, and each rocker arm of the flapper is assigned one of the nozzles, and a respective one of the control elements engaging each of the rocker arms for positioning the flapper.

7. A transducer of claim 2 wherein each of the control elements comprises an electromagnetic actuator controlled and energized by the electrical input signal.

8. A transducer of claim 7 wherein a rocker mount of a flapper is positioned such that when the electromagnetic actuators are de-energized pressures at the nozzles are substantially equal.

9. A transducer of claim 2 wherein one of the control elements comprises a spring and the other control element comprises an electromagnetic actuator.

10. A transducer of claim 9 wherein the spring acts on a rocker mounted flapper such that when the actuator is de-energized one nozzle is closed and the other nozzle is open.

11. A transducer of claim 2 wherein the setting unit, the control elements, and a nozzle-flapper assembly are housed together in a housing and the pneumatic amplifier is outside the housing.

12. A pneumatic actuator system, comprising: a pneumatic actuator;a transducer, said transducer comprising a pressure input connected to a source of pressure,a setting unit setting the pneumatic output signals by use of the electrical input signal,the setting unit being designed to generate the two pneumatic output signals separately and reciprocal to each other as a function of the input signal; andeach of the two output signals being connected to a respective pneumatic amplifier whose output is connected to respective inputs of said pneumatic actuator.

13. A system of claim 12 wherein said pneumatic actuator comprises first and second pneumatic working chambers, each separate from the other the output of one of the pneumatic amplifiers connecting to the first working chamber and the output of the other pneumatic amplifier connecting to the second pneumatic working chamber.

14. A transducer, comprising: at least one electrical input signal and two separate magnetic output signals;a pressure input connected to a source of pressure and a setting unit setting the pneumatic output signals by use of the electrical input signal; andthe setting unit providing the two pneumatic output signals separately and reciprocal to each other as a function of the input signal.